Leaderboard

Leaderboard backed by Redis in Node.js, basic on Promise.

https://www.npmjs.com/package/leaderboard-promise

Installation

$ npm install leaderboard-promise

API

#Constructor

var lb = new Leaderboard('name', [options], [redisOptions|redisClient])

Creates a new leaderboard or attaches to an existing leaderboard.

###Options

• pageSize - default: 50

  Page size to be used when paging through the leaderboard.

• reverse - default: false

  If true various methods will return results in lowest-to-highest order.

##Methods

• add(member, score)

  Ranks a member in the leaderboard.

  lb.add('member', 100).then(function(){
    // completed, do something
  }).catch(function(error){
    //failed
  });
  

• incr(member, score)

  Increments the score of a member by provided score and ranks it in the leaderboard. Decrements if negative.

  lb.incr('member', 2).then(function(){
    // completed, do something
  }).catch(function(error){
    //failed
  });
  

  now the score to the member would be 102.

• highest(member,score)

  Set a member`s highest score by provided score and ranks it in the leaderboard. If new score is less than old score in the leaderboard, it will keep the old scores.

  lb.highest('member',103).then(function(){ // completed, do something }).catch(function(error){ //failed }); now the score to the member would be 103.

• rank(member)

  Retrieves the rank for a member in the leaderboard.

  lb.rank('member').then(function(rank){
    // rank - current position, -1 if a member doesn't
  }).catch(function(error){
    //failed
  });
  

• score(member)

  Retrieves the score for a member in the leaderboard.

  lb.score('member').then(function(score){
     // score - current score, -1 if a member doesn't
  }).catch(function(error){
    //failed
  });
  

• list([page])

  Retrieves a page of leaders from the leaderboard.

  lb.list().then(function(list) {
    // list - list of leaders are ordered from
    // the highest to the lowest score
    // [
    //   {member: 'member1', score: 30},
    //   {member: 'member2', score: 20},
    //   {member: 'member3', score: 10}
    // ]
  });
  

• at(rank)

  Retrieves a member on the spicified ranks.

  lb.at(2).then(function(member) {
    // member - member at the specified rank i.e who has 2nd rank,
    // null if a member is not found
    // {
    //   member: 'member1',
    //   score: 30
    // }
  });
  

• rm(member)

  Removes a member from the leaderboard.

  lb.rm('member').then(function(removed) {
    // removed - false in case the removing member 
    // doesn't exist in the leaderboard.
    // true - successful remove
  });
  

• total()

  Retrieves the total number of members in the leaderboard.

  lb.total().then(function(number) {
    // captain obvious
  });
  

• numberInScoreRange(min,max)

  Returns the number of members in the leaderboard with a score between min and max.

  lb.numberInScoreRange(10,100).then(function(number){
    // number - the number of members
  });
  

• membersInRankRange(beginRank,endRank)

  Returns the list of members in the leaderboard between beginRank and endRank.

  lb.membersInRankRange(10,100).then(function(list){
    // list - the list of members
  });
  

License

MIT. Copyright (c) 2015 zhaotianze <[email protected]>

Author: zhaotianze